There remains a compelling need for improved ways to detect and quantify toxic and/or hazardous chemical species found at existing or potential Superfund sites. Better analytical techniques could reduce the cost of monitoring, help improve remediation methods, and more accurately assess the health risks associated with hazardous and toxic species. We have developed methods to produce novel nanoparticles, arrays, and structures that could be used for chemical analysis, and propose here several approaches that combine evolving methods with the characterization and monitoring needs of Superfund. They are linked by their use of small scale properties to develop new methods that should be faster, easier, smaller, and/or less expensive. The technologies on which we will focus could ultimately lead to a number of nanometer-based devices which are portable and robust, and which can be employed at commercial facilities or in-the-field for environmental monitoring. Our specific aims are to : 1. Develop low-cost sensors and sensor arrays for measuring chemical species such as arsenic and mercury using nanoparticle properties that can be probed optically and electronically. 2. Develop methods to identify biomolecules (specific antibodies/antigens used in bioremediation) by probing their unique local electronic structure using electron tunneling. 3. Investigate the use of new manufactured nanostructured materials for molecular detection, including structures such as carbon nanotubes and coated nanoparticles. The aims are divided into four tasks: Gas Phase Detection of Heavy Metals Using Nanoparticle Complexes with Laser Fragmentation Spectroscopy, Mercury Detection with Gold Nanoparticles, Surface Enhanced Raman Spectroscopy Detection of Arsenic Species, and the Detection of Bioremediation Organisms using Electronic Cell Typing. This project will investigate using the different and sometimes unique behavior of materials as their size shrink below 100 nm to develop new methods to detect chemical and biological species found at existing or potential Superfund sites. New sensors could reduce the cost of monitoring, help improve remediation methods, and more accurately assess the health risks associated with hazardous and toxic species.